A method to 3D print a programmable continuum actuator with single material using internal constraint

Soft continuum robots require differential control of channel pressure across several modules to trace 3D trajectories at the tip. For current designs such actuators, sheathing is required prevent radial expansion when chambers are pressurized. With recent development soft materials additive manufacturing, printing has become a promising fabrication method for robots. However, most actuators based on molding, which not designed printing. This paper proposes an internal constraint-based actuator single material printing, with tunable design parameters render pre-defined motions. The constraint maximizes superiority rapid prototyping solution in terms customizing high speed and freedom. constraints come form beam elements that only limit undesired (up ∼14% conventional design) but also allows be pressurized higher driving ∼160%) maximum bending angle ∼320%) compared no-beam design. By tuning parameter q (determined by number beams n per cross-section sections k along axial direction), we can desired movement under specific p. We show numerical simulation hardware experiment results achieve specified twisting motions following this approach.